Linux

Two physical drives. Install windows first in one, then Linux on the other. If you don't do this order windows boot manager will take over and you'll have to boot Linux from bios.

My aproach was to use two drives. I had Windows on the first, then disconected it and installed Linux on the second. That way I dont have grub and use F11 to open the bios bootloader to select the system I want.

My first line of investigation here would be virtualization. It will solve the "don't mess with my Linux install" problem and will let you use the windows apps you need at the same time as the Linux apps you normally use. Also VMs have all their other useful features like snapshots and portability.

I did this in the distant past and it was quite convenient having the VM instead of a dual boot.

I like rEFInd

If you insist on dual-boot: two separate physical drives.

Otherwise: use linux with a windows vm.

One thing I've been trying lately that's a bit different: I happen to have an old SSD that had an enclosure with it (kind of like this) which essentially turns it into an external USB drive.

I then used Rufus to install Windows on that drive, using the "Windows To Go" option and also checking the option to not allow Windows to access the internal drives. That way, my laptop can just happily run Linux by itself, and if I need to use Windows for anything I can just plug the drive in, hit F12 on boot and choose to boot from that drive instead. The added bonus is that Windows also can't mess with anything on my regular system or monkey about with the boot loader.

I've only had it on there for about a week but it seems to be working perfectly fine so far!

Oh and also Rufus gives you the option to start with a local account already set up, so you don't have to do the MS online account bullshit. And then after install I used ShutUp10 to turn off as much telemetry as I could.

The most painless way to dual-boot is to install something that's not Windows alongside something else that's not Windows.

I would recommend going for the IoT LTSC versions of Windows.

https://massgrave.dev/windows_ltsc_links

Is there a reason you need a dual book instance instead of a VM or even WINE?

Unless you need direct access to hardware and if you have enough RAM, you can probably avoid dual booting altogether.

1. Get 16gb of ram and CPU less than 5 years old.

2. Install Windows 11 in a VM

3. Install the virtio drivers from the Fedora project link

4. Profit

The default actually works pretty well these days.

Messing with the EFI partition, for instance by attempting to have two of those on separate disks, will probably cause you more pain than Windows will. As far as I understand, only one EFI partition can be configured in BIOS as the boot partition, so you will have to change the configuration in BIOS whenever you want to boot to the other OS.

Windows does have a history of changing the default EFI bootloader once in a while; however your chosen bootloader is still there, just not marked as the default anymore. A Windows app like EasyUEFI will let you change the default back.

Like others have said, I just use two drives, and I can boot into Windows with GRUB.

However, these days, I just do a VM with GPU passthrough. (I installed a second graphics card in my PC just for this.)

Swappable hard drives

I have a ThinkPad with easy access to the hard drive. It's one screw, remove a small panel and slide out the hard drive, slide in a new hard drive and reinstall the panel and screw. It all takes about a minute.

I have a drive for my Linux setup and another for windows.

I gave up setting up dual boot setups because I'm not as skilled or capable and I've lost entire setups in the past due to updates and changes and it was constantly frustrating for me. So I figured that just swapping hard drives was the easiest for me. No configuration, no changes and neither OS can interfere with one another.

I use my Linux as my daily driver for everything and windows when I need something from windows. I only ever use windows maybe once a month or once every second month. I spend more time regularly updating windows than in actually using it.

I put windows 11 live on a £20 USB drive, and it hasn't messed with my Linux install at all

Tiny10 on a VM

I'm sluggishly in the middle of the same thing.

Getting a second drive just for windows I think is a good approach. If you were to do so, it's important that you remove all other drives while installing windows, otherwise the Windows installer will put its boot files into whatever existing EFI partition it finds.

Then using something like https://github.com/Raphire/Win11Debloat you should be good to go with a relatively clean setup.

To have a local account, I use Rufus to setup the usb installer in a way that it automatically creates the local account, and it can also disable the secure boot and tpm requirements from the installer if you want. Though I think rufus is a windows program only. I know there's the "OOBE" approach for the local account, but I haven't done that before. That could be an option too

If by "these days" you mean a motherboard that supports UEFI, then it honestly doesn't matter anymore. Your board controls the boot order, and there isn't an MBR for Windows to mess with anymore. Just plan out your partitioning careful before hand, and if you plan on using a lot of files in both OS's, make a plain storage partition that is easily mounted under Windows (NTFS does not count).

Honestly, aside from a very scant number of apps or games, there isn't a real need to dual boot anymore. If you can't run something under Proton or Wine, having a Windows VM will get the job done.

If your windows software works in a vm or wine then that might be a better choice for you.

The only thing windows will do with to a Linux install anymore is mess up the boot. People still say two separate drives is the optimal choice to prevent this but it really doesn’t save you from anything but fat fingering your own partitions during the install process and if the disks are the same size/interface/manufacturer it doesn’t do much there either.

So as has always been the case since dual booting existed: install windows first, saving the space you want to use for Linux then install whatever you want. Have your distributions preferred method of repairing failed boot on hand so that when something breaks unexpectedly you can fix it. Often it’s more than a boot repair tool, but an entire bootable environment that can be used for all kinds of purposes.

Use uup dump and rufus to make a windows installer and put it on a usb. I specifically recommend rufus as opposed to dd or other normal way of doing things because it has special options regarding windows oobe and requirements that will be invoked on use.

It doesn’t matter if you choose 10 or 11. Both can be had in ltsc channels. Dealers choice, you’re the one with software that needs it!

a bootable removable medium that can display and chainload all the installed OSes

I added a second SSD to my windows laptop and installed Linux on it. I configured the BIOS to boot from this second SSD. Painless!

Windows doesn't mess with the Linux install anymore, that was with BIOS boot. Just make sure the EFI partition is big enough so you can fit both.

Using modern UEFI booting with a 1GB shared ESP and grub2 has worked just fine for me in the last 8 years. os-prober has always just found the Windows install and generated the necessary boot entry for grub. Windows has never trespassed into the Fedora or Ubuntu folder of the ESP as far as I can tell.

Having another PC with minimum requirements only for Windows?

Others have answered your dual-booting question pretty well. However, along the lines of "minimal" Windows, it's not generally recommended to fuck with the system as that can break things. There are scripts that can strip a lot of the problems, though. I can't remember any off the top of my head.

As for not requiring an account, I have old ISOs of Win11 and Win10 where the unplugging my ethernet cable trick gets me around signing into a Microsoft account. Not sure if it works on the ISO you get from Microsoft now, however. And if you have built-in WiFi, I think there's a way to disable it in the command prompt before you install.

Edit: Win10 is going to hit EOL in the near future. I am going to use it until then. It's got a lot fewer concerns (for me) than Win11, unless Microsoft keeps filtering Win11 shit into it.

As for the second question: Windows 11 IoT LTSC has yet to be mentioned here - the only things that can stop you from using it are legality and convenience.

I'm not sure if W10 has an IoT LTSC version, but W10 LTSC does exist.